KR101283367B1 - Liquid crystal display and method for manufacturing the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of controlling the phase difference between a reflection area and a transmission area by adjusting a pretilt angle without the need for patterning of a compensation film and an embedded phase. It is about a method.
According to the present invention, a high quality and a wide viewing angle can be secured even without a patterning process of a compensation film and a built-in retarder. Since the FFS mode is used, the liquid crystal molecules positioned on the pixel electrode may rotate due to the elastic torque of adjacent liquid crystal molecules, and thus have high transmittance characteristics. In addition, the single gamma characteristic can be adjusted by adjusting the thickness of the insulating layer coated on the reflective area, and the optical characteristics can be set by controlling the tilt angle of the liquid crystal. There is an effect that can be implemented.

Description

Liquid crystal display and its manufacturing method {LIQUID CRYSTAL DISPLAY AND METHOD FOR MANUFACTURING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of controlling the phase difference between a reflection area and a transmission area by adjusting a pretilt angle without the need for patterning of a compensation film and an embedded phase. It is about a method.

The liquid crystal display may be classified into a transmissive type and a reflective type liquid crystal display mode according to the light source used. Transmissive liquid crystal display mode is a form of displaying information by adjusting the amount of light according to the arrangement of liquid crystals by injecting artificial light from the backlight (backlight) attached to the back of the liquid crystal panel to the liquid crystal. The mode is a form in which information is displayed by reflecting external natural or artificial light and adjusting light transmittance according to the arrangement of liquid crystals. Since the transmissive liquid crystal display mode uses an artificial back light source, a bright image can be realized even in a dark external environment. However, if the power consumption is high and the surrounding environment is bright, the visibility of the display is poor. On the other hand, the reflective liquid crystal display mode has a structure in which most of the light is dependent on external natural light or artificial light source, so that it is thinner and lighter than the transmissive liquid crystal display mode and has low power consumption. However, visibility is low in the dark environment and has a disadvantage of difficult to implement high quality.

Recently, in order to overcome the shortcomings of the two types of liquid crystal display modes and to implement only the advantages, the transflective liquid crystal display device, which is a device that can select and use two modes appropriately according to a need, is mainly used. The transflective liquid crystal display device is generally used in a double cell gap structure using various compensation films to combine two modes in one pixel because the initial phase difference value and the on-off phase delay change of the reflecting part and the transmitting part are different. However, the use of the compensation film not only degrades the image quality characteristics of the transmission region, but also increases the thickness of the product and increases the manufacturing cost. In addition, the additional manufacturing process for the double cell gap structure is a cost increase factor.

In order to solve the above problems, by using the FFS (Fringe Field Switching) mode and Low Twisted Nematic (LTN) mode, a liquid crystal display device that can secure a wide viewing angle, express a clear image quality and improve the problem of cost increase to provide.

In another aspect, the present invention provides a method of manufacturing the liquid crystal display device that does not require a large amount of compensation film and the patterning process of the built-in retarder.

In the liquid crystal display device according to the present invention,

A first substrate and a second substrate on which transmission and reflection regions are defined; A common electrode and a lower insulator layer sequentially formed on the first substrate; A pixel electrode formed on the lower insulator layer and having a lattice shape in a transmissive area and a plain shape in a reflective area; A reflection layer formed on the pixel electrode of the reflection area; An upper common electrode formed in the reflective region under the second substrate; And a liquid crystal formed between the first substrate and the second substrate, wherein the liquid crystal is oriented without a twist angle in the transmission region, and the liquid crystal is a predetermined twist angle and a pretilt angle in the reflection region. It includes a liquid crystal layer that is provided and aligned.

The twist angle of the liquid crystal in the reflection area may be 50 to 70 degrees.

The liquid crystal of the reflective region may have a pretilt angle greater than that of the liquid crystal of the transmissive region.

The pretilt angle of the reflection area liquid crystal may be controlled such that the phase delay value of the reflection area satisfies λ / 4.

The liquid crystal display may have the same cell gap between the transmission area and the reflection area.

The pixel electrode of the transmission region may be patterned to have a width of 1 to 10 μm and a gap between the pixel electrodes to 1.5 to 20 μm.

The liquid crystal display may further include an upper insulating layer or a color filter layer under the upper common electrode of the reflective region and under the second substrate of the transmissive region.

The liquid crystal display may further include an upper insulating layer or a color filter layer under the upper common electrode of the reflective region so that the phase delay value of the reflective region satisfies λ / 4.

In the liquid crystal display, the liquid crystal director in the transmission region is initially oriented parallel to the transmission axis of the lower polarizing plate, and the liquid crystal director in the reflection region has a predetermined tilt angle and a twist angle. When the voltage is applied, the liquid crystal phase delay values of the transmission region and the reflection region may be λ / 2 and λ / 4, respectively.

In the liquid crystal display device manufacturing method according to the present invention,

Providing a first substrate and a second substrate on which transmission and reflection regions are defined; Sequentially forming a common electrode and a lower insulator layer on the first substrate; Forming a pixel electrode on the lower insulator layer in a lattice shape in a transmissive area and a plain shape in a reflective area; Forming a reflective layer on the pixel electrode of the reflective region; Forming an upper common electrode in a reflection area under the second substrate; And forming a liquid crystal layer between the first substrate and the second substrate, wherein the liquid crystal is aligned in the transmission region without a twist angle, and in the reflection region, the liquid crystal is a predetermined twist angle and a pretilt angle. forming a liquid crystal layer oriented to have an angle).

The forming of the liquid crystal layer may include controlling the twist angle by using an optical alignment method, irradiating an ion beam, or rubbing the liquid crystal.

The liquid crystal layer forming step may control the pretilt angle by using a photoalignment method, irradiating an ion beam, or irradiating ultraviolet rays to a liquid crystal doped with reactive mesogen (RM). It may include.

The forming of the liquid crystal layer may include controlling the twist angle to 50 to 70 degrees, and controlling the pretilt angle such that the phase delay value of the reflective region has λ / 4.

The method may further include forming an upper insulating layer or a color filter layer under the upper common electrode of the reflective region and under the second substrate of the transmissive region.

 The method may be to drive the liquid crystal display as a single driving circuit by adjusting the thickness of the upper insulating layer or the color filter layer of the reflective region.

The method may further include forming an upper insulating layer or a color filter layer under the upper common electrode of the reflective region, wherein the method adjusts the thickness of the upper insulating layer or the color filter layer of the reflective region. The phase delay value can be controlled to be λ / 4.

According to the present invention, a high quality and a wide viewing angle can be secured even without a patterning process of a compensation film and a built-in retarder. Since the FFS mode is used, the liquid crystal molecules positioned on the pixel electrode may rotate due to the elastic torque of adjacent liquid crystal molecules, and thus have high transmittance characteristics. In addition, the single gamma characteristic can be adjusted by adjusting the thickness of the insulating layer coated on the reflective area, and the optical characteristics can be set by controlling the tilt angle of the liquid crystal. There is an effect that can be implemented.

1 is a cross-sectional view of a single cell gap liquid crystal display device using low twisted nematic (LTN) liquid crystals in a reflective region.
2 is a graph showing initial light leakage according to the twist angle of the liquid crystal in the reflection region.
FIG. 3 is a graph showing initial light leakage according to the pretilt angle of the liquid crystal in the reflection area when the cell gaps of the reflection area and the transmission area are equal to 4 μm.
4 is a graph showing transmittance curves and reflectance curves according to the thickness and voltage of the color filter layer in the reflection region.
FIG. 5 is a graph illustrating normalized transmittance curves and reflectance curves according to voltage application when the thickness of the color filter layer is 3 μm in the reflective region.
6 shows an iso-contrast ratio curve when the wavelength of incident light is 550 nm. (a) shows a transmission area and (b) shows a reflection area.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

Referring to FIG. 1, a liquid crystal display according to an exemplary embodiment of the present invention may include a first substrate 10, a first substrate 20, a common electrode 30, a lower insulator layer 40, and a pixel electrode 50. 50 ′), a reflective layer 60, an upper common electrode 70, and a liquid crystal layer 80.

The present invention can be applied to a transflective liquid crystal display device in which a transmission region and a reflection region are defined between the first substrate 10 and the second substrate 20.

The transflective liquid crystal display expresses a display in a transmissive type in a dark environment such as a room, and a reflective type in a bright outdoor environment with sunlight. Therefore, you can see the LCD screen by reflecting the sun or ambient light in the daytime or bright place without turning on the backlight of the phone, and you can greatly reduce the power consumption by turning on the backlight of the phone in the dark so that you can see the LCD screen. Widely used in portable information communication devices such as PDAs.

1 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

The first substrate 10, the common electrode 30, and the lower insulator layer 40 are formed. Generally, the board | substrate used for this invention can use glass or a plastic board. Other known methods, materials, and techniques may also be used, without any limitation.

The common electrode 30 corresponds to the pixel electrode for driving the liquid crystal in the liquid crystal cell, and serves to maintain a reference voltage.

The lower insulating layer 40 may be made of silicon oxide, silicon nitride, or the like, and other known methods, materials, and techniques may be used, and the present invention is not limited thereto.

Pixel electrodes 50 and 50 'are formed on the lower insulator layer 40. The pixel electrodes 50 and 50 'are formed in a grid shape in which the predetermined intervals are spaced apart from each other in the transmissive area, and are formed in a plain shape in the reflective area.

The electrode structure of the transmissive region is a fringe field switching (FFS) mode in which both the common electrode 30 and the pixel electrode 50 'are positioned on a first substrate and driven by a fringe electric field.

The reflective region uses a low twisted nematic (LTN) mode driven by a vertical electric field when a common electrode 70 is added to the upper portion to apply a voltage.

The reflective layer 60 is formed on the pixel electrode 50 in the reflective region. External light incident by the reflective layer 60 can be reflected.

The surface of the reflective layer 60 may be formed with a plurality of embossed shapes consisting of a plurality of curved surfaces in order to increase the reflection efficiency of the light.

As the method for forming the embossing, for example, light is irradiated to the surface of a resin substrate made of a photosensitive resin layer or the like through a mask pattern, and a plurality of fine spherical recesses adjacent to each other are formed by developing. Aluminum, silver, or the like may be deposited or plated on the surface of a plurality of formed resin substrates to form a reflective layer having an embossed shape.

In the reflective region of the present invention, a common electrode 70 is formed. Therefore, when a voltage is applied, it can be driven by a vertical electric field.

The present invention includes a liquid crystal layer 80 formed between the first substrate 10 and the second substrate 20. The liquid crystal layer 80 is horizontally aligned on an upper portion of the pixel electrode 50 ′ formed in the transmission region and an upper portion of the reflective layer 60 formed in the reflective region.

The liquid crystal layer 80 of the reflective region is aligned to have a predetermined twist angle and a pretilt angle, and the liquid crystal layer 80 of the transmissive region is aligned without a twist angle. That is, parallel to the transmission axis of the lower polarizing film.

The twist angle means a direction angle between the directors on which the directors on one surface of the two support plates of the twisted nematic cell are projected on the other support plate.

The twist angle of the reflection area liquid crystal may be formed smaller than 90 degrees, preferably 50-70 degrees, and most preferably around 64 degrees. The liquid crystal of the reflective region may be aligned to twist from the bottom to the top while having the twist angle. That is, in the reflective region, when the lower liquid crystal array direction is oriented at 20 to 40 degrees with respect to the transmission axis of the upper polarizer, the upper liquid crystal array direction is coincident with the transmission axis of the lower polarizer, and thus the upper liquid crystal array direction is distorted 50 to 70 degrees. Can be.

As shown in FIG. 2, as the twist angle of the liquid crystal is out of the range of 50 to 70 degrees, the contrast ratio decreases as the light leakage in the initial dark state increases, so that the image quality is deteriorated. Do.

In order to change the alignment direction of the liquid crystal under the transmission region and the lower reflection region, a light alignment method, a method of irradiating an ion beam, or a method of rubbing the liquid crystal may be used.

The pretilt angle means an angle between the support plate surface and the adjacent liquid crystal director. In the present invention, the pretilt angle of the liquid crystal of the reflective region may be greater than the pretilt angle of the liquid crystal of the transmissive region.

More specifically, the phase delay value of the reflection area is such that the angle satisfying λ / 4 When the pretilt angle of the liquid crystal of the reflective region is adjusted to be larger than the pretilt angle of the liquid crystal of the transmissive region, the reflection region and the transmissive region between the first substrate 10 and the second substrate 20 are adjusted. It is possible to match the optical state of a single cell gap liquid crystal display device having the same cell gap.

That is, in the transflective liquid crystal display, the optical state of the transflective liquid crystal display can be controlled by an easy process of controlling the tilt angle of the liquid crystal in the transmissive region without the complicated process of compensating for the different optical characteristics of the reflective and transmissive regions. You can hit it.

In the liquid crystal display device, the initial liquid crystal director in the transmission region is oriented parallel to the transmission axis of the lower polarizing plate, and the liquid crystal director in the reflection region has a predetermined tilt angle and twist angle. When the voltage is applied, the liquid crystal of the transmission region and the reflection region may have a phase delay value of λ / 2 and λ / 4, respectively.

In order to make the phase difference dΔn of the reflecting region equal to half of the phase difference dΔn of the transmissive region, ultraviolet rays are irradiated to the liquid crystal doped with a photoalignment method, an ion beam irradiation method, or a reactive mosegen (RM). The pretilt angle of the liquid crystal in the reflective region may be adjusted by using the method. (d is the cell gap, Δn is the birefringence value of the liquid crystal)

In addition, the image quality may be improved by adjusting a pretilt angle of the reflective region liquid crystal. For example, when the cell gaps of the reflection area and the transmission area are equal to 4 μm, the pretilt angle of the reflection area liquid crystal is preferably adjusted to about 40 to 48 degrees, more preferably around 44 degrees. That's good. As shown in FIG. 3, the light leakage of the initial dark state increases in the range beyond 40 to 48 degrees.

The control of the pretilt angle is to adjust the dΔn value of the reflective region to λ / 4. As the cell gap d increases, the birefringence value Δn decreases, so the pretilt angle value is reduced. Is in an increasing relationship.

The pixel electrode 50 ′ of the transmission region may be patterned to have a width of 1 to 10 μm and a gap between the pixel electrodes to 1.5 to 20 μm. The pixel electrode 50 ′ is a transparent electrode made of indium tin oxide (ITO) positioned under each pixel, and serves to apply an electric field to the liquid crystal layer. The patterning on the pixel electrode 50 'is to control the liquid crystal director by applying an electric field between the common electrode and the pixel electrode. When patterning out of the above range, it may be difficult to control the liquid crystal director.

The liquid crystal display according to the exemplary embodiment may further include an upper insulating layer or a color filter layer 100 under the upper common electrode 70 of the reflective region and under the second substrate 20 of the transmissive region. Can be. A single gamma characteristic of the reflection area and the transmission area may be realized by the upper insulating layer or the color filter layer 100.

That is, the upper common layer 70 is present on the second substrate 20 of the reflective region and the pixel electrode 50 is present on the first substrate 10. This will affect the vertical electric field. Therefore, the influence of the electric field felt by the liquid crystal director is less affected, thereby affecting the threshold voltage, driving voltage, and reflectance of the reflectance graph according to voltage application. That is, by adjusting the thickness of the upper insulating layer or the color filter layer 100, it is possible to match the single gamma characteristic of the reflective region and the transmission region.

The liquid crystal display according to the exemplary embodiment of the present invention may further include an upper insulating layer under the upper common electrode of the reflective region so that the phase delay value of the reflective region satisfies λ / 4. In other words, the upper insulating layer is added so that dΔn of the reflection area is half of the transmission area to match the optical state of the reflection area and the transmission area. (d is the cell gap, Δn is the birefringence value of the liquid crystal)

A color filter layer may also be used instead of the insulating layer. The color filter not only acts as an insulator, but also has the advantage of reducing the thickness of the product. In addition, the reflection area has advantages in terms of color reproducibility because light passes twice through the color filter layer and transmission area passes once.

The second substrate 20 may be formed on the liquid crystal layer 80 of the transmission region and the upper common electrode 70 of the reflective region, and a polarizing film 90 may be formed thereon. The polarizing film may also be formed under the first substrate 10. The transmission axes of the polarizing film below the first substrate 10 and the polarizing film above the second substrate 20 have a difference of 90 degrees from each other.

In the transmission region, since the rubbing direction of the liquid crystals arranged in the initial horizontal direction before voltage application coincides with the transmission axis of the polarizing film, an initial dark state is maintained. When a voltage is applied, the liquid crystals are rotated due to the fringe electric field between the pixel electrode 50 'and the common electrode 30, thereby implementing a bright state.

When the initial phase delay value of the liquid crystal between the polarizing film and the reflective layer is λ / 4 or π / 2 in the reflective region, the reflectance formula is as follows.

R ∝ cos ² δ (V)

Here, δ is a phase difference between light oscillating in the long axis direction of the liquid crystal molecules and light oscillating in the direction perpendicular to the long axis direction, and is defined as δ = 2πdΔn _eff / λ. d is the cell gap, Δn _eff is the effective birefringence value of the liquid crystal according to the voltage, and λ is the wavelength of the incident light. Therefore, when the initial state δ of the liquid crystal layer is π / 2, the reflectance value becomes 0, indicating a dark state. When voltage is applied, the liquid crystal molecules are perpendicular to the substrate, and the δ of the liquid crystal layer becomes 0. As it passes through the liquid crystal layer without being reflected in the phase delay, the bright state is realized.

Hereinafter, a method of manufacturing a liquid crystal display device according to an exemplary embodiment of the present invention having the above structure will be described.

The manufacturing method of the present invention includes providing a first and a second substrate, forming a common electrode / lower insulating layer, forming a pixel electrode, forming a reflective layer, forming an upper common electrode, and forming a liquid crystal layer.

First, a first substrate 10 and a second substrate 20 in which transmission and reflection regions are defined are provided. The common electrode 30 and the lower insulator layer 40 are sequentially formed on the first substrate. The pixel electrodes 50 and 50 'are formed on the lower insulator layer 40. The pixel electrodes 50 and 50 'are formed in a lattice shape in the transmission area and in a plane shape in the reflection area. The lattice shape of the transmissive region may have a pattern of pixel electrodes having a width of 1 μm to 10 μm and a gap between pixel electrodes of 1.5 μm to 20 μm.

The reflective layer 60 is formed on the pixel electrode 50 in the reflective region. The reflective layer 60 serves to reflect external light incident from the outside. The surface of the reflective layer 60 may be formed with a plurality of embossed shapes consisting of a plurality of curved surfaces in order to increase the reflection efficiency of the light. As the method for forming the embossing, for example, light is irradiated to the surface of a resin substrate made of a photosensitive resin layer or the like through a mask pattern, and a plurality of fine spherical recesses adjacent to each other are formed by developing. Aluminum, silver, or the like may be deposited or plated on the surface of a plurality of formed resin substrates to form a reflective layer having an embossed shape.

Next, the upper common electrode 70 is formed in the reflective region under the second substrate 20. The liquid crystal layer 80 is formed between the first substrate 10 and the second substrate 20.

In the transmission region, the liquid crystal is aligned without a twist angle, and in the reflection region, the liquid crystal is aligned to have a predetermined twist angle and a pretilt angle.

The forming of the liquid crystal layer 80 may control the twist angle by using a photoalignment method, by irradiating an ion beam, or by rubbing the liquid crystal.

In addition, the pretilt angle may be controlled by using a photo-alignment method, irradiating an ion beam, or irradiating UV light onto a liquid crystal doped with reactive mesogen (RM).

The photoalignment method controls the orientation by illuminating the light. Photo-alignment can be achieved by using isomeric structures of photosensitive molecular groups, partial photolysis of polyimides, partial multimerization of materials with photoactive molecular groups, such as cinnamates or coumarins, or diffraction patterns By changing the surface structure (SRG), it is possible to control the twist angle and the pretilt angle.

The ion beam irradiation may control the twist angle and the pretilt angle by adjusting at least one of an ion beam irradiation angle, an ion beam energy, an ion beam current density, and an ion beam irradiation time.

In the method of irradiating ultraviolet rays after doping reactive mesogen (RM) in the liquid crystal layer, mesogen refers to a photocrosslinkable polymer copolymer containing a mesogen group of liquid crystal properties Used to be. When the polarized ultraviolet light is irradiated to the mesogen, the anisotropy of the mesogen is induced, and then heat treatment is performed to improve the directivity of the liquid crystal. The mesogenic group is a polymer material exhibiting liquid crystallinity in a predetermined temperature range or in a solution state. The reactive mesogen (RM) may include a substance or compound, such as rod-shaped, banana-type, board-type, or disc-type, which may induce a liquid crystal phase reaction. The reactive mesogen (RM) may include, for example, acrylate, methacrylate, epoxy, oxetane, vinyl-ether, styrene, thioene group, or the like as a reactor. The reactive mesogen is suitably 0.1 to 10% by weight, preferably 1.5 to 2.5% by weight based on the total weight of the liquid crystal layer. This is because it may be difficult to control the phase delay value of the reflective liquid crystal when it is out of the range.

The manufacturing method of the liquid crystal display includes forming an upper insulating layer or a color filter layer 100 under the upper common electrode 70 of the reflective region and under the second substrate 20 of the transmissive region. Can be. A single gamma characteristic of the reflection area and the transmission area may be realized by the upper insulating layer or the color filter layer 100.

Hereinafter, the electro-optical characteristics of the liquid crystal display device having the above structure will be described.

In order to study the electro-optical properties, a computer simulation was performed by the 2 × 2 Jones extended matrix method. The surface orientation of the liquid crystal molecules was assumed to be strong anchoring energy. In the liquid crystal display according to the exemplary embodiment of the present invention, the cell gap between the reflection area and the transmission area is set to 4 μm, and a single cell gap structure is used. The pretilt angles of the liquid crystals in the transmissive and reflective areas were applied at 2 and 44 degrees, respectively. The arrangement direction of the initial liquid crystal molecules in the transmission region is parallel to the transmission axis of the lower polarizing film. In the reflection region, the alignment direction of the lower liquid crystal is 26 degrees relative to the transmission axis of the upper polarizing film. In the end, 64 degrees were twisted. In addition, in order to match the single gamma characteristics of the reflective and transmissive regions, the color filter layer 100 was coated under the upper common electrode 70 in the reflective region, and the simulation was performed while adjusting the thickness thereof. It is assumed that the transmittance of one polarizing film is 41% and that of two polarizing films is 35%.

FIG. 4 is a graph showing transmittance and reflectance according to voltage while forming a thickness I of the color filter layer in the reflection region from 0 to 3.5 μm. In this case, the color filter layer 100 is used as the material to be coated on the upper common electrode of the reflective region instead of the insulator layer. The color filter not only acts as an insulator, but also has the advantage of reducing the thickness of the product. In addition, the reflection area has advantages in terms of color reproducibility because light passes twice through the color filter layer and transmission area passes once.

 Referring to the influence of the color filter layer 100, even if the color filter layer 100 is present on the second substrate 20, since the electrode is not located on the second substrate 20 is affected by the color filter layer 100. Do not receive. However, the reflective region includes a common electrode 70 having a planar shape on the second substrate 20 and a pixel electrode 50 on the first substrate 10, whereby a color filter layer disposed at an upper portion when a voltage is applied ( 100) affects the strength of the vertical electric field. Therefore, the influence of the electric field felt by the liquid crystal director is less affected, thereby affecting the threshold voltage, driving voltage, and reflectance of the reflectance graph according to voltage application. Therefore, by adjusting the thickness of the color filter located above the reflection area, it is possible to match the single gamma characteristic of the reflection area and the transmission area.

As shown in FIG. 4, when the thickness I of the upper color filter in the reflective region is increased from 0 μm to 3 μm, it can be seen that the transmittance and reflectance graphs according to voltage have the form of a single gamma curve. When the difference between the long axis of the liquid crystal in the region and the slit angle of the pixel electrode is α = 10 degrees, the threshold voltages of the transmission region and the reflection region are both less than 1.5V, and the driving voltage is formed around 4.2V. .

FIG. 5 is a graph in which a transmittance and a reflectance curve are corrected according to voltages of a transmission region and a reflection region when the thickness I of the upper color filter is 3 μm. The driving voltages of the reflective and transmissive regions are 4.2V, and the reflectance and transmittance curves are similar to each other when voltage is applied. Since gamma curves of each region are almost identical, they can be driven by a single driving circuit.

6 illustrates a contrast curve of a transmission area and a reflection area in the liquid crystal display according to the exemplary embodiment of the present invention. In the transmissive area, the area with contrast ratio of 10: 1 is 60 degrees or more in all directions, and in the reflection area, the area with contrast ratio of 5: 1 is 40 degrees in all directions. That is above. Since the viewing angle characteristic is mainly determined by the transmission region, the liquid crystal display according to the exemplary embodiment of the present invention shows excellent wide viewing angle characteristics.

So far we looked at the specific embodiment of the present invention. The disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation, and the present invention may be embodied in a modified form without departing from the essential features thereof.

10: first substrate 20: second substrate
30 common electrode 40 lower insulator layer
50, 50 ': pixel electrode 60: reflective layer
70: upper common electrode 80: liquid crystal layer
90 second substrate 100 color filter layer

Claims (14)

A first substrate and a second substrate on which transmission and reflection regions are defined;
A common electrode and a lower insulator layer sequentially formed on the first substrate;
A pixel electrode formed on the lower insulator layer, the pixel electrode having a lattice shape in the transmission area and a plane shape in the reflection area;
A reflection layer formed on the pixel electrode of the reflection area;
An upper common electrode formed in the reflective region under the second substrate; And
It is formed between the first substrate and the second substrate, the liquid crystal is aligned in the transmission region without the twist angle, and in the reflection region the liquid crystal is a predetermined twist angle and a pretilt angle (Pretilt angle) A liquid crystal display device including a liquid crystal layer oriented therein, wherein the liquid crystal display device has the same cell gap between the transmission area and the reflection area, and a twist angle of the liquid crystal in the reflection area is 50 to 70 degrees, The liquid crystal in the reflective region has a pretilt angle of a predetermined angle at which the phase delay value satisfies λ / 4, and the pretilt angle of the reflective liquid crystal is larger than the pretilt angle of the transmissive liquid crystal. Display. delete delete delete The liquid crystal display device according to claim 1, wherein the pixel electrode of the transmissive region is patterned to have a width of 1 to 10 mu m and a gap between pixel electrodes to 1.5 to 20 mu m. The liquid crystal display of claim 1, wherein the liquid crystal display further comprises an upper insulating layer or a color filter layer under the upper common electrode of the reflective region and under the second substrate of the transmissive region. delete Providing a first substrate and a second substrate on which transmission and reflection regions are defined;
Sequentially forming a common electrode and a lower insulator layer on the first substrate;
Forming a pixel electrode on the lower insulator layer in a lattice shape in the transmission area and a plane shape in the reflection area;
Forming a reflective layer on the pixel electrode of the reflective region;
Forming an upper common electrode in a reflection area under the second substrate; And
A liquid crystal layer is formed between the first substrate and the second substrate, wherein the liquid crystal is aligned in the transmission region without a twist angle, and in the reflection region, the liquid crystal is a predetermined twist angle and a pretilt angle. A liquid crystal display manufacturing method comprising the step of forming a liquid crystal layer oriented to have a)
The manufacturing method is formed such that the cell gap of the transmission region and the reflection region is the same,
In the liquid crystal layer forming step, the twist angle is controlled to 50 to 70 degrees, and the pretilt angle is controlled so that the phase delay value of the reflective region is λ / 4. A pretilt angle is formed larger than the pretilt angle of the transmissive liquid crystal. The method of claim 8, wherein the forming of the liquid crystal layer comprises controlling the twist angle by using a photoalignment method, irradiating an ion beam, or rubbing the liquid crystal. Liquid crystal display device manufacturing method. The method of claim 8, wherein the forming of the liquid crystal layer is performed by using a photoalignment method, by irradiating ultraviolet rays to a liquid crystal doped with an ion beam (Beam), or doped with reactive mesogen (RM). Method of manufacturing a liquid crystal display device, characterized in that to control the (pretilt angle). delete delete delete delete

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